Differences in finger length have been repeatedly linked to a range of human traits, from aggression to musical ability to sexual orientation.
Take a look at your ring finger. Is it shorter or longer than your index finer? Well, if you’re a man, it’s probably longer. And there’s actually some research behind this to show why this could be.
When we’re in the womb, estrogen and testosterone are what control certain genes, including those that dictate the length of our finger. For men, that’s longer than our index finger, and for women, the ring finger being shorter than the index finger.
But scientists have also said that there could be links between the length of our fingers, and some human traits, including from musical ability, to aggression, to sexual orientation. What’s more, there could be more links to health problems, including autism, heart attacks, depression and cancer.
Whilst there has been evidence of the length of finger being caused by the sex hormones, they’ve been careful about this, as at no point yet, has causality been confirmed. That said, it could all just be a coincidence, or some other unexplained reason. However, after using genetic tools to change whether mice are effected by testosterone and embryos, they’ve been able to determine what effect this has. Namely, the male mice lacking testosterone, had shorter ring fingers than index finger, and for the male mice without estrogen, it was reversed. All this is also reversed for the female mice.
The testosterone makes the ring finger longer, by building up cell division, whilst the estrogen does the opposite, and slows the cell division, making it shorter overall.
This leads to scientists being able to look at our ring fingers, and being able to tell things about the womb where we were for up to nine or ten months. These irregularities in estrogen and testosterone in the womb, can also signify medical conditions, which could develop later on in life.